I added some info in bold based on comments below.
The new improved Standard Series has received three new models as of today, with a fourth on the way that is unlike any Standard Series model before it (but not allowed to be revealed until next Monday.)
The three new models are the D-17, 000-17 (short-scale,) and (about time!) the OM-45. I repeat, the OM-45 has returned!!!
There are also two very exciting new models added at the top of the Road Series, the DE Retro Plus and the 000E Retro Plus. These new Road Series instruments receive appointments that look a lot like the D-18 and 000-18. But while they retain the Road series Performing Artist neck profile (which I love) and Tusq saddle (which I am not crazy about) they have a full gloss body and a TORRIFIED top.
Meanwhile, back in Nazareth, PA, the 17s receive full Standard Series construction, including (according to my insider sources) "Genuine Mahogany" back, sides, and top, even if that is not reflected on the spec sheet (so no guarantee on how long they will remain thus.) They also feature the full-size dovetail neck joint with solid mahogany neck block, and the (new to the Standard Series in 2025) Sitka spruce Golden Era bracing, which has reduced mass and more-precise damping nodes thanks to the narrower peaks on each brace and tone bar, as found on the Modern Deluxe models.
They retain the satin finish of a pre-war Style 17 instrument, and the modest appointments that are now seen on the 15 Series (short pattern diamond fret markers on an ebony fingerboard,) which originated on the original 00-17 from the 1930s.
The OM-45 looks like the OM-45 introduced in 1990, with the large hexagon fret position markers. But otherwise, it has the vintage Martin appointments seen on recent Standard Series Martins and the GE bracing and the GE Modified Low Oval Profile neck shape that is as of today, is a NEW feature of all Standard Series Martins. This includes a more 1930s shaping to the volute to the back of the neck where it meets the headstock, along with the more vintage-esque heel shape that looks vintage but has less mass (e.g. as used on the Modern Deluxe Series) which result in a subtly different feel the entire neck compared to previous Standard Series models.
The new bracing is the same as used on the Modern Deluxe Series, only it is Sitka instead of Adirondack, and it is not torrefied.
It is not a typo. The D-28 now has scalloped bracing. But it retains the 1950s appointments rather than the 1930s look of the HD.
The D-35 retains the 1/4" non-scalloped braces. The major differences from last year's D-35 is how the struts of the X brace are tapered all the way to the center of the brace, but there is still no scallop out near the ends of the struts as they spread out across the bottom bout. It also gets the narrower bridge plate of the other 2025 Standard Series dreadnoughts.
The Authentic Series fingerboard depth is also NEW to all Standard Series models and was likewise adapted from the Modern Deluxe Series. This should allow more energy to make its way from the fretted strings down to the body where it will contribute to tone production. The change in fingerboard depth brought about other tweaks.
There is a "comfort bevel edge" where the fingerboard meets the mahogany neck that should be welcome by most players. The string spacing has received an (unannounced) tweak at the nut, and to the string angle as it crosses the nut between fingerboard and headstock has also changed. Known as "on-angle," this is yet another spec from pre-war Martins that founds its way on the modern Authentic Series models and now is being resurrected on the "standard" models that descended from those legendary Martins from the 1930s.
The keen-eyed among you may recognize how this new "GE" version of the High Performance neck had a sneak preview when C. F. Martin IV decided to release O'ahu HG-28 in late 2024, ahead of the NAMM show later this month.
Oh, and the Standard Series models now all sport either bone or ebony pins on the slightly reshaped bridge, which is likewise titled GE and has wings with less mass with the same goal of increased responsiveness.
A discussion of the newly "refreshed" Standard Series can be found on the Martins and More podcast, found on major pod platforms and YouTube, and of course full reviews of these new models will appear at One Man's Guitar as soon as my busy life allows me to edit the video from the factory and write up the exclusive reviews.